Getting ready to flush the DexCool out of my S2 L67 cooling system to switch to green. To be thorough, I want to drain the block too.

I have read posts about pulling the knock sensors, however when under the car today I noticed what looks to be drain plugs on each side of block.
It looks like a hex bolt head slightly recessed in a boss on the side of block.

Below are two cell phone pics looking up the front side of block from under the car.








Are these drain plugs for the block?
If so, how are they sealed (thread sealant, o-ring, copper washer)?


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All those bolts are oil pan bolts.

Remove the knock sensors. They are just to the sides of the oil pan in the middle of the motor from front (by water pump) to back (transmission).. have a one wire connector going to them. Each is round and will require a large socket to remove.

The bolt I was wondering about comes off the side of the block about 2" above the oil pan gasket, behind the starter. Just wondering if this can be an alternative to knock sensor removal.

Yep, that'* a drain plug. There is one on the other side, too.

Honestly..On a SII your best method of draining will be the knock sensor. Easier to get at IIRC as well.

I've rolled them over once the KS'* were removed and there is nothing left.

Thanks - that’* what I was wondering about .

I've drained coolant..thought I had it all.. then removed a knock sensor and ... poof..there'* the other 3 gallons.

Would having the system flushed at a garage and filled with non-Dex coolant do the trick too?

Sure, but why wouldn't you of all people do that yourself?

Oh, just a question..... Besides, a good high pressure flush can be a great thing....